According to the extensive, 50-year-old body of knowledge in object-oriented programming and design, good software designs are, among other characteristics, lowly coupled, highly cohesive, extensible, comprehensible, and not fragile. However, with the increased complexity and heterogeneity of contemporary software, this might not be enough. This paper discusses the practical challenges of object-oriented design in modern software development. We focus on three main challenges: (1) how technologies, frameworks, and architectures pressure developers to take design decisions that they would not take in an ideal scenario, (2) the complexity of current real-world problems require developers to devise not only a single, but several models for the same problem that live and interact together, and (3) how existing quality assessment techniques for object-oriented design should go beyond high-level metrics. Finally, we propose an agenda for future research that should be tackled by both scientists and practitioners in the near future. This paper is a call for arms for more reality-oriented research on the object-oriented software design field.